Glycolysis

Question 1

glycolysis

Answer 1

10 step anaerobic process in which glucose is broken down to 2 pyrovate and while doing this ATP is made. This is in the cytoplasm . This makes 2 ATP so its inefficient.

Question 2

Energy consuming phase

Answer 2

Required 1 ATP

Question 3

energy producing phase

Answer 3

makes 2 ATP and NADH which can make ATP

Question 4

How we get glucose to the cell?

Answer 4

GLUT, passive transport- facillitaed diffusion- are used to get glucose into the cell from blood stream.

Question 5

kinase

Answer 5

phosphorylate molecules

Question 6

hexokinase

Answer 6

found in all cells, makes glucose to glucose 6 phosphate to mantain glucose in the cell

Irreversible

Question 7

glucokinase

Answer 7

liver cells and beta cells of the pancreas, makes glucose to glucose 6 phosphate to mantain glucose in the cell. IRREVERSABLE

Question 8

phosphoglucoisomerase

Answer 8

makes an isomer from glucose 6 phosphate to fructose 6 phosphate

Question 9

How can we regulate PFK1?

Answer 9

its regulated by PFK2, it can phosphorylate F6P, but instead of 1C, phosphorylates the 2C making F-2,2-bP after meal high glucose, insulin its secreted so PFK2 its stimulated, making F26bP, stimulating PFK1 —-> accelerates the glycolysis fasting state low glucose beta cells secrete glucagon inhibiting PFK2, less F26bP, inhibiting PFK1, less PFK1 less glycolysis High energy states: ATP and citrate inhibit PF1

Question 10

How many G3P are per glucose molecule?

Answer 10

2

Question 11

Cellular respiration

Answer 11

production of ATP from glucose oxidation via glycolysis, the krebs cycle and the oxidative phosphorylation

Question 12

The average daily intake of _________ is 50% of calories digested

Answer 12

The average daily intake of carbs is 50% of calories digested

Question 13

Carbohydrates consumed:

Answer 13

starch 50%

sucrose 30%

lactose 6%

the other : glucose, fructose, srbitol cellulose, hemocellulose and pectins

Question 14

Carbs

Answer 14

Can be simple or complex sugars, composed of carbon, hydrogen and oxygen.

simple: glucose, fructose
complex: starch, glycogen, cellulose

Question 15

Starch

Answer 15

high molecular weight compund consisting of 1 polysaccharides- amylose and amylopectin

Question 16

glycogen

Answer 16

high molecular weight polysaccharide similar to amylopectin, but have 1,6- linkages

Question 17

How can we regulate glycolysis?

Answer 17

hexokinase- inhibited by glucose 6-P

PFK1- inhibited by ATP and activated by ADP

pyruvate kinase- activated by Fructose 1,6- biphosphate

Question 18

Glycolysis can produce intermediates for other pathways like _______, _________, and ___________

Answer 18

Glycolysis can produce intermediates for other pathways like amino acid, nucleic acid, and lipid metabolism

Question 19

erythrocyte

Answer 19

relies exclusively on glucose, during maturation loses subcellular organelles.

Question 20

What is the equation of glycolysis?

Answer 20

Glucose + 2NAD + 2Pi+ 2ADP ——> 2 pyruvates + 2 NADH + 2ATP + 2H + H2O

Question 21

Site of rxn for glycolysis

Answer 21

cytoplasm

Question 22

Site of transformation of pyruvate to Acetyl-CoA

Answer 22

mithocondrial matrix

Question 23

Site of krebs cycle

Answer 23

mitochrondial matrix

Question 24

site of oxidative phosphorilation

Answer 24

mithocondrial inner membrane

Question 25

which are the rate limiting steps in glycolysis?

Answer 25

Glucose to glucose 6 phosphate by hexokinase

PEP to pyruvate by pyruvate kinase

Question 26

steptococcus mutans and lactobacillus

Answer 26

Fermentation

anaerobic bacteria in oral cavity that grow optimally on refined fermemtable carbs. They thrive in acidic sites like teeth fissures and in gingival pocketThe acid produced by fermentation erode tooth enamel and dentin, and the hydroxyapatite matrix setting cavity formation.

Fluoride- integrates into the tooth surface forming fluorapatite which is more resistant to demineralization

Question 27

Blood test for diabetes

Answer 27

since RBC can metabolize glucose to lactose, acidification happens giving a false dx of hypoglycemia.

We can fix this by adding sodium fluoride or sulfhydryl reagents to inhibit glycolysis. This is because fluoride is a strong competito with endose and fluoride can form a complex with phosphate and Mg 2+ in the active site of the enzyme, blocking access of the substrate

Question 28

Pyruvate Kinase Deficiency

Answer 28

Most common hemolytic anemia. It’s a autonomic recessive disorder. We diagnose this by measuring erythrocyte levels of enzymes: thermal lability its shown, increase Km for PEP, and decrease activation by Fru-1,6- biphosphate.

This anemia can be mild to severe and its caused by inability to make enough ATP to mantain RBC ion gradients and cell shape. Some can tolerate because accumulation of 2,3-biphosphoglycerate lowers oxygen affinity, promoting O2 transport to muscle and fetus.

Question 29

Glycolysis in tumor

Answer 29

• tumors go glycolytic to increase source of Energy
• increase of glycolysis due to hypoxia inhibiting mitochrondial oxidative phosphorylation, metabolic need exceeds the supply of oxygen and nutrients from the blood. This may cause accumulation of lactate making a necrotic core.
• Some secrete sytokines promoting angiogenesis (vascularization) increasing fuel supply and enhancing tumor growth.
• Treatment? trying angiogenesis inhibitors